Feted by some as the greatest boxer of all time, Sugar Ray Robinson possessed one quality that gave him an edge over his opponents.

“To be a champ you have to believe in yourself when no one else will,” he insisted.

Director Antoine Fuqua, screenwriter Kurt Sutter and star Jake Gyllenhaal clearly believe in their hard-slugging drama about a former boxing legend, who hits the comeback trail in order to win back the custody of his young daughter.

Fuqua orchestrates testosterone-fuelled skirmishes inside the ring with brio, Sutter trades verbal blows with his snappy dialogue and Gyllenhaal trained intensively for six months with fight choreographer Terry Claybon to replicate the physicality and mentality of a fighter.

Ironically, for a film that packs a wallop during briskly edited bouts, Southpaw delivers only a few light jabs to our heart strings, almost all of which are landed by 12-year-old actress Oona Laurence.

At 124 minutes, Fuqua’s cliche-riddled contender expects us to go 12 rounds with training montages and a euphoric Eminem soundtrack before the final showdown of brawn against brains.

Southpaw is a rousing parable of triumph over adversity that won’t knock out any fans of The Champ, Rocky and other displays of pugilistic big screen machismo.

Gyllenhaal looks in peak physical shape, but mumbles his lines, some of which are incomprehensible. McAdams illuminates her limited scenes while Laurence proves she can cry on cue like a leaky tap.

Jackson plays his role with swagger, echoing the capitalist interests of modern sport when his bling-laden promoter grins: “If it makes money, it makes sense.”